[PATCH 15/17] net: convert net.passive from atomic_t to refcount_t
From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-06-28 11:56:33
Also in:
bridge, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- include/net/net_namespace.h | 3 ++- net/core/net-sysfs.c | 2 +- net/core/net_namespace.c | 4 ++-- 3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index fe80bb4..bffe0a3 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h@@ -5,6 +5,7 @@ #define __NET_NET_NAMESPACE_H #include <linux/atomic.h> +#include <linux/refcount.h> #include <linux/workqueue.h> #include <linux/list.h> #include <linux/sysctl.h>
@@ -46,7 +47,7 @@ struct netns_ipvs; #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) struct net { - atomic_t passive; /* To decided when the network + refcount_t passive; /* To decided when the network * namespace should be freed. */ atomic_t count; /* To decided when the network
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 65ea0ff..bdcf5dd 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c@@ -1444,7 +1444,7 @@ static void *net_grab_current_ns(void) struct net *ns = current->nsproxy->net_ns; #ifdef CONFIG_NET_NS if (ns) - atomic_inc(&ns->passive); + refcount_inc(&ns->passive); #endif return ns; }
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 26bbfab..50935eb 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c@@ -284,7 +284,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) LIST_HEAD(net_exit_list); atomic_set(&net->count, 1); - atomic_set(&net->passive, 1); + refcount_set(&net->passive, 1); net->dev_base_seq = 1; net->user_ns = user_ns; idr_init(&net->netns_ids);
@@ -380,7 +380,7 @@ static void net_free(struct net *net) void net_drop_ns(void *p) { struct net *ns = p; - if (ns && atomic_dec_and_test(&ns->passive)) + if (ns && refcount_dec_and_test(&ns->passive)) net_free(ns); }
--
2.7.4